Scientists have created microscopic sensors – up to 300 thousand devices fit on one coin. They use light for power and communication, and in the future, on their basis it will be possible to create a new generation of microsensors with high processing power and low power consumption. An article by researchers at Cornell University is published in PNAS.
Researchers have developed sensors about 100 microns in size – they are smaller in size than a speck of dust on a computer monitor. Despite their miniature size, they are equipped with an integrated circuit, solar cells and light-emitting diodes (LEDs), which allow them to use light for power and communication.
The main feature of the development is not the extremely small size of the devices, but a platform that allows them to be mass-produced. In the future, these devices can be used to create very energy-efficient sensors.
In order to adapt them for this purpose, scientists had to solve a rather complicated problem. The fact is that placing tiny microcircuits on the silicon wafer of the sensor is relatively easy, but adding LEDs to them is difficult because they are made of another material: gallium arsenide.
To transfer the LEDs onto a plate with electrical components and integrate them, the researchers developed a sophisticated assembly method that includes more than 15 layers of photolithography, 30 different materials, and more than 100 steps.
“In a sense, it’s an old idea to create chips and sensors based on an array of tiny sensors like these. But we were able to put this idea into practice, and also made the production of sensors massive. In the near future, we plan to produce these devices in millions”.
Newman McEwen, lead author of the study